A gas turbine engine generally includes a fan and a core arranged in flow communication with one another. A first portion of air over the fan may flow past the core through a bypass airflow (defined between the core and an outer nacelle) and a second portion of air over the fan may be provided to the core.
The core of the gas turbine engine generally includes, in serial flow order, a compressor section, a combustion section, a turbine section, and an exhaust section. In operation, the air provided to the core flows through the compressor section where one or more axial compressors progressively compress the air until it reaches the combustion section. Fuel is mixed with the compressed air and burned within the combustion section to provide combustion gases. The combustion gases are routed from the combustion section to the turbine section. The flow of combustion gasses through the turbine section drives the turbine section and is then routed through the exhaust section, e.g., to atmosphere.
Typical gas turbine engines also include a plurality of bleed air flow paths in airflow communication with the compressor section. For example, if the compressor section includes a low pressure compressor and a high pressure compressor, the plurality of bleed air flow paths can be in airflow communication with the low pressure compressor. Depending on certain operating conditions of the gas turbine engine, at least a portion of an airflow through the low pressure compressor can be diverted through the bleed air flowpaths to, e.g., the bypass airflow or atmosphere. Providing at least a portion of the airflow from the low pressure compressor through the bleed air flow paths to, e.g., the bypass airflow or atmosphere, may assist in controlling certain parameters of the gas turbine engine (e.g., reducing an overall pressure ratio of the compressor section). Reducing the overall pressure ratio can increase the stall margin of the compressor.
However, providing a portion of the airflow from the low pressure compressor through the bleed air flow paths can result in a decreased efficiency of the gas turbine engine. For example, any energy in the portion of the airflow from the low pressure compressor provided through the bleed air flow paths to atmosphere may be lost with such a configuration. Accordingly, a gas turbine engine capable of bleeding air from a compressor section while reducing unnecessary energy loss would be beneficial. More particularly, a gas turbine engine capable of capturing energy within a flow of bleed air would be particularly useful.